Genetics worksheet with answers

In pea plants, purple flowers (A) are dominant over white (a). A plant with genotype Aa is crossed with a plant with genotype Aa. What is the probability P that an offspring has purple flowers?

In pea plants, purple flowers (A) are dominant over white (a). A plant with genotype Aa is crossed with a plant with genotype Aa. What is the probability P that an offspring has white flowers?

Duchenne muscular dystrophy is X-linked recessive (allele d). A carrier mother, X^DX^d, has children with an affected father, X^dY. The mother's gametes run down the side. Click the cell for an affected son.

1. 1X^d × X^d
2. 2X^d × Y
3. 3X^D × X^d
4. 4X^D × Y

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an unaffected father, X^HY. The mother's gametes run down the side. Click the cell for an affected son.

1. 1X^h × X^H
2. 2X^h × Y
3. 3X^H × X^H
4. 4X^H × Y

A recessive condition affects 1 in 10000 of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

Two AaBb parents are crossed. Gene A gives yellow seeds (dominant) or green seeds; gene B gives tall plants (dominant) or short plants. Click the one cell for an offspring that is shows green seeds and is homozygous for tall plants.

1. 1ab × aB
2. 2ab × Ab
3. 3ab × ab
4. 4ab × AB
5. 5Ab × aB
6. 6Ab × Ab
7. 7Ab × ab
8. 8Ab × AB
9. 9aB × aB
10. 10aB × Ab
11. 11aB × ab
12. 12aB × AB
13. 13AB × aB
14. 14AB × Ab
15. 15AB × ab
16. 16AB × AB